[PIC] 4*4 Matrix Keypad Optimization help needed

#include<P30f5011.h>

int main()
{
	uart_init();
	while(1)
	{
		KeyPadScan();
		delay(100);
	}

}





const unsigned char keys[16]  =	  {0x11,0x12,0x14,0x18,
								   0x21,0x22,0x24,0x28,
								   0x41,0x42,0x44,0x48,
								   0x81,0x82,0x84,0x88};
 
															//[R][C]
const unsigned char key_char[16][4]=   {{'M','M','M','M'},  //[1][0]
							 			{'1',',','.','@'},	//[1][1]
										{'2','A','B','C'},	//[1][2]
										{'3','D','E','F'},	//[1][3] 
																		
										{'U','U','U','U'},	//[2][0]
										{'4','G','H','I'},	//[2][1]
										{'5','J','K','L'},	//[2][2]
										{'6','M','N','O'},  //[2][3]


										{'D','D','D','D'},	//[3][0]
										{'7','P','Q','R'},	//[3][1]
										{'8','S','T','U'},	//[3][2]
										{'9','U','V','W'},	//[3][3]

										{'E','E','E','E'},	//[4][0]
										{'*','X','Y','Z'},	//[4][1]
										{'0','0','0','0'},	//[4][2]
										{'C','C','C','C'}};	//[4][3]


unsigned char key_pos1=0,n=0;

void KP_INIT(void)
{
ADCON1bits.ADON = 0;	//ADC DISABLED
ADPCFG = 0xFFFF; 	      //Digital port active	
TRISB	= 	0x00F0;  //COL as I/P ROW as OP
LATB	=	0x0000;		//ALL LATB PINS LOW
printf("Key pad init done...\n");
}

void KeyPadScan( void )
{
unsigned char j=0,i=0;

PORTB=0x0F;  					 
if(PORTB != 0x0F )
{
for(i=0;i<4;i++)			
{
PORTB = 1<<i;						for(j=0;j<16;j++)
{
if((PORTB == keys[j]))
{
if(key_pos1 != j)
	n=0;						
key_pos1 = j;
					
 if(n==0 || n==1 || n==2 || n==3)
{							printf("%c\n",key_char[j][n]);
	n++;
	if(n==4)
	n=0;
	break;
}}}}}}